1. Field of the Invention
The present invention relates to local area networks (LANs) generally and, more particularly, to a novel wireless local area network (WLAN) for use in vehicles that reduces the hard wiring of electronic devices in the vehicle, while maintaining access to messages on the vehicle bus.
2. Background Art
WLANs, which typically provide communications via a radio frequency network, are widely used in offices, for example, to wirelessly interconnect a number of pieces of electronic equipment such as computers and facsimile transmitters/receivers. Such an arrangement eliminates the need to hard wire such components and provides flexibility in that the pieces of electronic equipment can be easily relocated to different locations around the premises by simply moving the equipment, without having to perform any rewiring.
As cellular telephones, pagers, and other electronic equipment have become more and more numerous, the use thereof in vehicles has become more and more common. Typically, such items are connected via radio frequency to a wireless wide area network (WWAN) which provides radio frequency communications via satellite and/or terrestrial antennas. When the cellular telephones or pagers are located in a vehicle, they are hard wired to a vehicle bus originating in the AM/FM radio head control unit, or any other electronic module in the vehicle, the cellular telephones or pagers communicating via radio frequency with the WWAN. Such an arrangement adds cost to the vehicle and reduces flexibility in that the hard wired components cannot be easily relocated within the vehicle, used in proximity to the vehicle, or used away from the vehicle.
Some other “wireless” communication systems of various types include the following:
At least one bus system uses a WWAN function to transmit voice and data communications to a fixed roadside reader. The roadside reader communicates over a WLAN with an in-vehicle wireless transmit/receive unit (TRU) that is connected to the vehicle bus. The roadside reader is not mobile and does not have the capability to communicate inside and outside of the vehicle. Remote keyless entry devices provide data communication to the vehicle mounted TRU by way of a WLAN. The TRU provides a gateway that distributes the data over various wired vehicle busses. The system does not communicate with a WWAN.
In-vehicle cellular telephone systems have used dummy handsets that employ radio frequency and/or infrared to connect from a dummy handset to the TRU. While these systems have a WLAN, they have the WLAN TRU fixed or embedded in the vehicle and it cannot be used outside the vehicle. Furthermore, in the case of infrared, the system cannot interface with multiple devices on the WLAN and is very line-of-sight and directional in the connectivity to the infrared sensors.
None of the foregoing systems provides an in-vehicle WLAN to interconnect electronic devices in a vehicle.
Accordingly, it is a principal object of the present invention to provide a WLAN for in-vehicle communications with electronic devices.
It is a further object of the invention to provide such a WLAN that eliminates or reduces the amount of hard wiring required to interconnect such devices.
It is another object of the invention to provide a voice and/or data connection from the WWAN to the WLAN and on to the vehicle wired bus.
It is an additional object of the invention to provide such a WLAN that is easily and economically implemented.
Other objects of the invention, as well as particular features, elements, and advantages thereof, will be elucidated in, or be apparent from, the following description and the accompanying drawing figures.